sysdeps/alpha/fpu/s_rint.c

   1 /* Copyright (C) 2000 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Richard Henderson.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <math.h>
  21
  22
  23 double
  24 __rint (double x)
  25 {
  26   if (isless (fabs (x), 9007199254740992.0))    /* 1 << DBL_MANT_DIG */
  27     {
  28       double tmp1, new_x;
  29       __asm (
  30 #ifdef _IEEE_FP_INEXACT
  31              "cvttq/svid %2,%1\n\t"
  32 #else
  33              "cvttq/svd %2,%1\n\t"
  34 #endif
  35              "cvtqt/d %1,%0\n\t"
  36              : "=f"(new_x), "=&f"(tmp1)
  37              : "f"(x));
  38
  39       /* rint(-0.1) == -0, and in general we'll always have the same
  40          sign as our input.  */
  41       x = copysign(new_x, x);
  42     }
  43   return x;
  44 }
  45
  46 weak_alias (__rint, rint)
  47 #ifdef NO_LONG_DOUBLE
  48 strong_alias (__rint, __rintl)
  49 weak_alias (__rint, rintl)
  50 #endif